In order to fabricate a superconducting wire for a superconducting apparatus, a long superconducting wire rod is required. Generally, a long superconducting wire rod is obtained by successively connecting a plurality of superconducting wire rods.
As a structure connecting a plurality of superconducting wire rods, a connection structure described in Japanese Patent Laying-Open No. 2011-238513 (PTD 1) is proposed. A first superconducting wire rod described in PTD 1 has a superconducting layer, internal solder layers, and reinforcing layers. Further, the superconducting wire rod described in PTD 1 has an edge portion. A second superconducting wire rod described in PTD 1 has the same structure as that of the first superconducting wire rod.
The superconducting layer has a first surface and a second surface. The reinforcing layers are provided on the first surface and the second surface. However, no reinforcing layer is provided on a region of the first surface located on an edge portion side. Namely, the superconducting layer is exposed in the region of the first surface located on the edge portion side. The internal solder layers are provided between the reinforcing layers and the first and second surfaces to join the reinforcing layers to the superconducting layer.
The connection structure for superconducting wire rods described in PTD 1 has the first superconducting wire rod, a second superconducting wire rod, and a connection solder layer. The superconducting layer of the first superconducting wire rod exposed in the region of the first surface located on the edge portion side is arranged to face the superconducting layer of the second superconducting wire rod exposed in the region of the first surface located on the edge portion side. The superconducting layer of the first superconducting wire rod exposed in the region of the first surface located on the edge portion side is joined to the superconducting layer of the second superconducting wire rod exposed in the region of the first surface located on the edge portion side, by connection solder.